A wheel bearing device has been evolved from a structure referred to as a first generation in which a double-row rolling bearing are used in combination to a second generation in which a vehicle body mounting flange is integrally provided in an outer member, and has been further developed to a third generation in which one of two inner raceway surfaces of the double-row rolling bearing is formed in an outer circumference of a hub wheel having the wheel mounting flange, and further, to a fourth generation in which one of the two inner raceway surfaces of the double-row rolling bearing is formed in the outer circumference of the hub wheel, and the other is formed in an outer circumference of an outer joint member of a constant velocity universal joint.
For example, in Patent Literature 1, one example of the wheel bearing device referred to as the third generation is described. As shown in FIG. 15, this wheel bearing device includes a hub wheel 152 having a flange 151 extending in an outer diameter direction, a constant velocity universal joint 154 in which an outer joint member 153 thereof is fixed to this hub wheel 152, and an outer member 155 disposed on an outer circumferential side of the hub wheel 152.
The constant velocity universal joint 154 includes the outer joint member 153, an inner joint member 158 disposed inside a mouse portion 157 of this outer joint member 153, a ball 159 disposed between this inner joint member 158 and the outer joint member 153, and a holder 160 that holds the ball 159. Moreover, female splines 161 are formed in an inner circumferential surface of a central hole of the inner joint member 158, and male splines formed at an end portion of a shaft not shown are inserted into this central hole. The female splines 161 of the inner joint member 158 and the male splines of the shaft are fitted, by which the inner joint member 158 and the shaft are coupled so as to be able to transmit a torque.
The hub wheel 152 has a cylindrical portion 163 and the flange 151, and in an outer end surface 164 (an end surface on an outboard side) of the flange 151, there is projected a short-cylindrical pilot portion 165 to attach a wheel and a brake rotor, which are not shown. The pilot portion 165 is made up of a large-diameter portion 165a and a small-diameter portion 165b, the brake rotor is externally fitted on the large-diameter portion 165a, and the wheel is externally fitted on the small-diameter portion 165b. 
A fitting portion 166 is provided in an outer circumferential surface of an end portion on an inboard side of the cylindrical portion 163, and an inner ring 167 of a rolling bearing is fitted on this fitting portion 166. A first inner raceway surface 168 is provided in the vicinity of the flange 151 in an outer circumferential surface of the cylindrical portion 163, and a second inner raceway surface 169 is provided in an outer circumferential surface of the inner ring 167. Moreover, a bolt attachment hole 162 is provided in the flange 151 of the hub wheel 152, and a hub bolt to fix the wheel and the brake rotor to the flange 151 is fitted into the bolt attachment hole 162.
The outer member 155 of the rolling bearing has double-row outer raceway surfaces 170, 171 in an inner circumference thereof, and a flange (a vehicle body mounting flange) 182 in an outer circumference thereof. The first outer raceway surface 170 and the second outer raceway surface 171 of the outer member 155 are opposed to the first inner raceway surface 168 of the hub wheel 152, and the second inner raceway surface 169 of the inner ring 167, respectively, and rolling elements 172 are interposed between these raceway surfaces.
A shaft portion 173 of the outer joint member 153 is inserted into the cylindrical portion 163 of the hub wheel 152. At a shaft end portion of the shaft portion 173, a screw portion 174 is formed, and male splines 175 are formed in an outer diameter portion on the inboard side from this screw portion 174. Moreover, female splines 176 are formed in an inner diameter surface of the cylindrical portion 163 of the hub wheel 152, and press-fitting the shaft portion 173 into the cylindrical 163 of the hub wheel 152 allows the male splines 175 on the side of the shaft portion 173 and the female splines 176 on the side of the hub wheel 152 to be fitted.
A nut member 177 is screwed and attached onto the screw portion 174 of the shaft portion 173, thereby fixing the hub wheel 152 and the outer joint member 153. At this time, a seating surface 178 of the nut member 177 and an outer end surface 179 of the cylindrical portion 163 abut, and an end surface 180 on the outboard side of the mouse portion 157 and an end surface 181 of the inner ring 167 of the rolling bearing abut. This allows the hub wheel 152 to be sandwiched between the nut member 177 and the mouse portion 157 with the inner ring 167 interposed.